1) Several data sets of the tryptophan synthase crystals from Salmonella typhimurium have been refined. The refined structures have confirmed the original observation at lower resolution of a tunnel for the passage of indole generated in the first reaction to the active site of the second enzyme. Mutants are being examined with a view to elucidating the dynamic nature of this tunnel and of the site interaction in the complex. 2) Inhibitor complexes of rhizopus pepsin have been analyzed by X- ray diffraction with a view to obtaining more information concerning the mechanism of action. 3) A method has been developed for the joint refinement of structures determined by X-ray diffraction and by NMR. 4) Crystals have been obtained for the complex of a Y-box protein from Xenopus oocytes with a DNA oligomer.